function outputArg1 = isll(inputArg1)
%ISLL 此处显示有关此函数的摘要
%   inputArg1 为需要计算的序列

inputArg1 = reshape(inputArg1, [], 1);

yconv = conv(inputArg1,flip(conj(inputArg1)));
PwrSeq = abs(yconv);

% 搜寻主瓣宽度,主瓣宽度以第一零点为界
[MaxPwr, MaxPwrIndex] = max(PwrSeq);
rMainlobeZero = MaxPwrIndex+1;
while true
    if((rMainlobeZero+1) > length(PwrSeq))
        break;
    end
    if(PwrSeq(rMainlobeZero) < PwrSeq(rMainlobeZero+1))
        break;
    else
        rMainlobeZero = rMainlobeZero + 1;
    end
end
lMainlobeZero = 2 * MaxPwrIndex - rMainlobeZero;

PwrSeq(lMainlobeZero:rMainlobeZero, 1) = 0;

outputArg1 = sum(PwrSeq);

end

